Benthic invertebrates in an arctic mountain stream, Brooks Range, Alaska

Journal of Research of the U.S. Geological Survey
By: , and 



 A 1-day, late-summer reconnaissance of the Dietrich River, Alaska, determined species composition and diversity of benthic invertebrates and examined the correlation between stream order and invertebrate distribution. Benthic invertebrates were collected by dip net, drift net, and 10-rock collections, and results were combined for each station. Forty-nine taxa were identified from 5 stations representing stream orders 1 through 5. Aquatic insects comprised 88 percent of all taxa and 97 percent of all individuals from the Dietrich River. Diptera, especially Chironomidae, was the most abundant, followed by Plecoptera. Diamesinae was abundant at the headwaters, decreasing downstream; Orthocladiinae exhibited the reverse distribution pattern. Diversity of collections generally increased downstream. The station collections were compared using coefficients of similarity, cluster analysis, and taxonomy. Collections from adjacent stations were most similar and similarity decreased with increasing distance. The fauna was tentatively divided into zones with characteristic communities: a Diamesinae-Simuliidae fauna in zone I (stream order 1), zone II, a region of transition (orders 2-4), and an Orthocladiinae-Plecoptera-Ephemeroptera fauna in zone III (order 5). The fauna compares closely with that of other arctic streams. Although not conclusive, the benthic invertebrate results are consistent with the hypothesis that stream order is related to lotic biological communities.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Benthic invertebrates in an arctic mountain stream, Brooks Range, Alaska
Series title Journal of Research of the U.S. Geological Survey
Volume 5
Issue 4
Year Published 1977
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Description 9 p.
First page 519
Last page 527
Country United States
State Alaska
Other Geospatial Dietrich River
Online Only (Y/N) N
Additional Online Files (Y/N) N
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